He who would assist a lord of men in harmony with the Dao will not assert his mastery in the kingdom by force of arms. Such a course is sure to meet with its proper return.
Wherever a host is stationed, briars and thorns spring up. In the sequence of great armies there are sure to be bad years.
A skilful (commander) strikes a decisive blow, and stops. He does not dare (by continuing his operations) to assert and complete his mastery. He will strike the blow, but will be on his guard against being vain or boastful or arrogant in consequence of it. He strikes it as a matter of necessity; he strikes it, but not from a wish for mastery.
When things have attained their strong maturity they become old. This may be said to be not in accordance with the Dao: and what is not in accordance with it soon comes to an end.

Now arms, however beautiful, are instruments of evil omen, hateful, it may be said, to all creatures. Therefore they who have the Dao do not like to employ them.
The superior man ordinarily considers the left hand the most honourable place, but in time of war the right hand. Those sharp weapons are instruments of evil omen, and not the instruments of the superior man; – he uses them only on the compulsion of necessity. Calm and repose are what he prizes; victory (by force of arms) is to him undesirable. To consider this desirable would be to delight in the slaughter of men; and he who delights in the slaughter of men cannot get his will in the kingdom.
On occasions of festivity to be on the left hand is the prized position; on occasions of mourning, the right hand. The second in command of the army has his place on the left; the general commanding in chief has his on the right; – his place, that is, is assigned to him as in the rites of mourning. He who has killed multitudes of men should weep for them with the bitterest grief; and the victor in battle has his place (rightly) according to those rites.

And it occurred to me that in similarly ancient times at the opposite end of Eurasia from where Laozi sat somebody said:

Put your sword back into its place; for all who take the sword will perish by the sword.

— Matthew 26:52

And yes, Laozi was writing circumstances very different to those in which Jesus was speaking, but the two sentiments are similar and not unrelated.

And it occurred to me that if people living 2000 and more years ago in places as diverse as Roman-occupied Palestine and Warring States China could come to such similar conclusions as to the value of weapons and violence, then surely, just like the Golden Rule, it must be a principle and a value so universal it can be found in one formulation or another in many different cultures, many different philosophical and religious traditions, many different times from ancient to modern, many different places.

Apparently people have done studies counting up deaths and their causes through history and have concluded that as time has marched on, people’s chances of dying early from violent causes have gradually trended downwards. Our species has been getting less violent, not that you’d know it from watching the news (so don’t watch the news). There is evidence that we are in fact slowly evolving from barbarity into something approaching civilisation. But for all the painfully slow cultural evolution over the four or five thousand years for which we have some form or another of written records (of varying and frequently dubious quality), some things about our species remain stubbornly the same. And so the writings and ramblings of ancient prophets, loudmouths, poets, madmen, sages, rabble rousers and philosophers remain as relevant now as when Socrates was handed his cup of hemlock.

And yet for all of our slow evolution into finding less drastic, more civilised methods of dispute resolution than grabbing the nearest weapon and lashing out and for all the people who have read the two books just quoted over the last couple of thousand years, our leaders still seem awfully eager to bellow their bellicose rhetoric, beat their drums, and march us off to War.

The Ancients warned us: War may sometimes be necessary, but it is never good, and really should be avoided if at all possible.